That's right: shorter videos for the 20 min break with slides, theory, recipe and call to actions (for discussion and proof-reading by you and other members of the community).
Also, maybe more show than tell. If it might be possible, show us how you run a session. Often, it is this unspoken content, that makes it most terrifying for new GMs or which makes more experienced GMs still nervous. To see how you handle this, might be very helpful.
And if you want to put the dot on the i, you could afterwards post a video in which you comment on your own techniques, what you thought in this moment, what surprised you and why you decided to go for this or that decision and on how you experienced the session in general and what you believe your players experienced.
Also, I would suggest to put the main topic of our hobby into the focus at least once: FUN.
What is fun in this game, what does the GM need to understand about fun, what is fun for different players and GMs, and how can we increase the fun? I have researched a whole lot about it in the past and had never had the time to write something about this (being occupied with many other interesting topics), but I am looking forward to share then.